Anytime the Capitals are an underdog my first look is going to be on them. Washington has retained its core group that helped win the Stanley Cup two seasons ago. The Capitals have had all summer to think about being drummed out of the playoffs in the first round by Carolina last year. 
The Capitals should be sky-high for this matchup against the defending Stanley Cup champion Blues. St. Louis is still on Cloud 9 after winning its first Stanley Cup championship in its 51-year history. 
The Blues will be raising their Stanley Cup banner before the game in celebration. So the Blues aren't likely to be as focused and motivated as the Capitals. 
Washington has enjoyed good success when playing in St. Louis winning five of the past seven times there.